Americans with irregular heartbeats to double: study

NEW YORK (Reuters Health) - If current trends continue, the number of Americans who experience a dangerous irregular heartbeat called atrial fibrillation will more than double in the next 16 years, according to a new study.

In 2010, some five million U.S. adults had been diagnosed with atrial fibrillation, or AF, but the study projects about 12 million cases by the year 2030.

That's a best guess, said study coauthor Dr. Daniel Singer, professor of medicine at Harvard Medical School in Boston, but the potential range is between 7 million and 17 million Americans diagnosed with the condition.

"By any estimate, there are going to be lots of (predominantly older) Americans with AF in 2030," Singer told Reuters Health by email.

"It's a very big problem," said Dr. Jonathan Piccini, who studies the evaluation and management of atrial fibrillation at Duke University Medical Center in Durham, North Carolina.

One in four adults over the age of 40 will experience AF at some point, said Piccini, who was not involved in the new study.

Singer and his colleagues based their estimate on the number of AF cases between 2001 and 2008 in a large insurance claims database of 14 million people.

Based on those figures, the researchers report in the American Journal of Cardiology that the number of Americans with AF grew from 220 per 100,000 population in 2002 to 350 per 100,000 in 2007.

Taking into account U.S. Census Bureau projections for the increase in numbers of older Americans in the coming decades, the researchers estimate there will be a total of 12.1 million people in the U.S. living with AF in 2030.

That represents an average annual growth rate of 4.6 percent in the number of people with AF.

Irregular heartbeats are most common among older people, but the projected growth in cases would result from aging as well as increases in risk factors for AF, including obesity and diabetes, the authors write.

The irregular, usually very fast, heartbeat can cause painful palpitations, limit the ability to exercise or lead to heart failure, Singer said.

"Even AF patients without symptoms are at five-fold increased risk of stroke, which often leads to major disability or death," he said.

Overall, 15 percent of strokes in the U.S. are a result of AF, according to Singer.

The study was funded by Bristol-Myers Squibb and Pfizer, which manufacture apixaban (Eliquis), a drug used to reduce stroke risk in people with AF. Singer has consulted for multiple companies with business interests related to AF, including Bristol-Myers Squibb.

Among the limitations of the study the authors acknowledged was that it only included privately insured people, so the estimate may not reflect the broader U.S. population.

However, most studies agree the number of AF cases will continue to increase to some degree, which puts individuals at risk and costs the health system.

"More atrial fibrillation in the population is not a good thing," Piccini said. "It means more heart failure, more strokes and higher mortality."

The condition can be treated with bloodthinning medications like apixaban and the older drug warfarin, surgeries and lifestyle changes, depending on how often symptoms arise.

To lower the risk of developing AF, especially older adults should "make sure they get good preventive health care, including diagnosis and treatment of hypertension, diabetes or sleep apnea," Piccini said. "Maintaining a healthy body weight and active lifestyle are also important."